/* ----------------------------------------------------------------------
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
*
* $Date:        19. March 2015
* $Revision: 	V.1.4.5
*
* Project: 	    CMSIS DSP Library
* Title:	    arm_cfft_init_f32.c
*
* Description:	Split Radix Decimation in Frequency CFFT Floating point processing function
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* -------------------------------------------------------------------- */

#include "arm_math.h"
#include "arm_common_tables.h"

/**
 * @ingroup groupTransforms
 */

/**
 * @addtogroup RealFFT
 * @{
 */

/**
* @brief  Initialization function for the floating-point real FFT.
* @param[in,out] *S             points to an arm_rfft_fast_instance_f32 structure.
* @param[in]     fftLen         length of the Real Sequence.
* @return        The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
*
* \par Description:
* \par
* The parameter <code>fftLen</code>	Specifies length of RFFT/CIFFT process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096.
* \par
* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
*/
arm_status arm_rfft_fast_init_f32(
    arm_rfft_fast_instance_f32 *S,
    uint16_t fftLen)
{
    arm_cfft_instance_f32 *Sint;
    /*  Initialise the default arm status */
    arm_status status = ARM_MATH_SUCCESS;
    /*  Initialise the FFT length */
    Sint = &(S->Sint);
    Sint->fftLen = fftLen / 2;
    S->fftLenRFFT = fftLen;

    /*  Initializations of structure parameters depending on the FFT length */
    switch (Sint->fftLen)
    {
    case 2048u:
        /*  Initializations of structure parameters for 2048 point FFT */
        /*  Initialise the bit reversal table length */
        Sint->bitRevLength = ARMBITREVINDEXTABLE2048_TABLE_LENGTH;
        /*  Initialise the bit reversal table pointer */
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
        /*  Initialise the Twiddle coefficient pointers */
        Sint->pTwiddle     = (float32_t *) twiddleCoef_2048;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_4096;
        break;
    case 1024u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE1024_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_1024;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_2048;
        break;
    case 512u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_512;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_1024;
        break;
    case 256u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_256;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_512;
        break;
    case 128u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_128;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_256;
        break;
    case 64u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE__64_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_64;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_128;
        break;
    case 32u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE__32_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_32;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_64;
        break;
    case 16u:
        Sint->bitRevLength = ARMBITREVINDEXTABLE__16_TABLE_LENGTH;
        Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
        Sint->pTwiddle     = (float32_t *) twiddleCoef_16;
        S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_32;
        break;
    default:
        /*  Reporting argument error if fftSize is not valid value */
        status = ARM_MATH_ARGUMENT_ERROR;
        break;
    }

    return (status);
}

/**
 * @} end of RealFFT group
 */
